AHhhh Yes,

That is how the error started. But please read the report of James Shirk commander of the USS Lexington at St Charles, Ar. on the White River, July 2, 1862, ORN 1, 23, page 187-188 with particular attention to the last paragraph on page 188.

According to all the reports the Union navy had maintained a constant presence in the White River between the time of the report you cite of June 19th and this report on July 2nd.

During that two week period of time, the USS ST LOUIS and BENTON with a Draft of 6 feet each reported that they had repeatly stirred up the bottom of the White River and had drug bottom on several occations.

The CSS Ponchartrain had a Draft of 10 feet.

The Union ships had proceeded 63 miles above St Charles during that time and not discovered the Ponchartrain. And were forced back due to falling waters.

And Shirk's report of July 2nd seems to confirm that the report of the Ponchartrain being in the White River on the 19th was in error. That the Ponchartrain had been in Little Rock all the time.